1. Technical Field
The present invention relates to a technique for managing the data indicating an image that is written by a user on an image displayed by a display apparatus, such as a projector.
2. Related Art
There is a product called an interactive white board (hereinafter, referred to as an “IWB”). The IWB enables a user to perform pseudo-writing on an image, which is displayed on the display surface by a display apparatus such as a projector, using a pen type device or the like.
That is, the display apparatus displays an image showing the trajectory of the writing operation, which is performed on the display surface by the user, so as to be superimposed on an image already displayed on the display surface. As a result, pseudo-handwriting of figures or characters on the displayed image is possible.
Examples of the document that discloses the technique regarding the IWB include JP-A-2011-028629. According to the system disclosed in JP-A-2011-028629, an image showing the trajectory of infrared light, which is emitted to a screen from a pointer used at the time of presentation, is superimposed on an image projected from the projector to the screen. As a result, the user can write figures or characters on the image, which is being displayed on the screen, in a pseudo manner using a pointer.
In a meeting and the like using the IWB, there is a case where it is necessary to share some of the information written in the presentation materials or the like only between the attendees of the meeting. In such a case, an operation to select an image showing the information, which should not be known to people who are not the attendees of the meeting, of the written information and delete or encrypt it has been required in the related art.